powell



W. T. POWELL INTEROFFICE TRUNKING SYSTEM oct. 21, 1930.

original Filed Dec.

4, 1920 4 Sheets-Shea?l l INVENTOR WWW-RED T. POWELL ATTORNEY Re. 17,839k Oct. 21, 1930. w. T. PowLL.

l INTEROFFICE TRUNKING SYSTEM Original Filed Deo. 4, 1920 4Sheets-Sheet, 2

INVENTOR WWFRED 1: PUWELL Oct. 2l,A 1930. w. T. POWELL INTEROFFICETRUNKING SYSTEM Original Filed Deze; 4 Sheets-Shet 5 nro. .2.5

l wmrREntPowEu wpd E Pwd( ATTORNEY Oct. 2l, 1930.

W. T. POWELL l INTEROFFICE TRUNK I NG SYS TEM Original Filed Dec. 4,1920 4 Sheets-Sheet 4 Illli dvknwu avanzar mvENToR WWW-RED T. POWELLwif/Wi ATTORNEY- .WINFRED T. POWELL, or ROCHESTER,

Reissued Oct. 21, 1930 UNITED STATES PATENT oFFlcE- NEW YORK, ASSIGNORTO THE STROMBEBG;

CARLSON TELEPHONE MANUFACTURING COMPANY, OF ROCHESTER, NEVI-YORK, A.

CORPORATION OF NEW YORK INTEROFFICE TRUNKING- SYSTEM Original No.1,502,917, dated July This invention relates to telephone systems andmore particularly to systems having a plurality of oices or exchanges.

In former telephone systems, when calls originated in one oflice for asubscriber at a distant oiice, an operator known as an A operator,connected the answering 4end of her cord circuit to the line of thecalling subscriber and received the designation of the wanted line fromthis subscriber. The A operator then depressed an voffice key by whichher telephone set was connected to an order wire leading to thedistantwanted oice over which wire the A operator repeated the number ofthe wanted subscriber to a B operator at the distant office who assigneda trunk for use in completing this call. n The A loperator then insertedthe calling end of her cord circuit into the jack ofthe assigned trunk.rlhe B operator after'receiving the number of the wanted line proceededto test this line and, if idle, inserted the calling end of her cordcircuit into the multiple jack of the wanted line and signalled thewanted subscriber. The use of such an order wire has resulted in muchdelay, and great confusion resulting from the errors due to repeatingthe number thereover.

The present invention has for its purpose the elimination of the orderwire and provides in its stead automatic means for assigning an idletrunk to the vdistant office as the result of the operation of an oificekey and automatic. means indicates visually the designation of theautomatically selected trunk, so that the A operator can connect thecalling end of her cord circuit to the assigned trunk. At the distantoilice the B operator is informed of the number of the Wanted line bymeans of signals variably operated from the A operatorvs position.V

The main feature of .this invention is'the arrangement of circuits forthe manual interconnection of subscribers lines terminating at differentexchanges or oices without the use of the so-'called order orinstruction telephone circuits vbetween the operators at said exchanges.n

Another feature of this invention is the provision of means vforautomatically assign- 29, 1924, Serial No. 428,225, led December 4,1920. Applicatonfor reissue filed AprilV 6, 1826.

Serialy Noy 100,191, l

ing an idle trunk to a wanted exchange in response to the operation of akey individual to said oliice and means for automatically indicating thetrunk assigned.

Another feature of the invention resides in the means for registeringthe designation of a wanted line on registering means located at oneoiiice and for automatically repeating such registration at a distantoiice to variably and selectively actuate indicating means at thedistant office.

Other features will. appear from the detailed description andy appendedclaims.

The drawings, with Figures 1,".2 and 3 arranged in the order named andwith Fig. 4 placed belowFigs. 1 and 2 so that' the lines thereof meet,diagrammatically represent a portion of a telephoneV system employingthe present invention, The circuits shown on Fig.v 1 and' at the left ofthe heavygdashed Vline ofFig. 2 and the circuits of Fig. 4, representaportion of the equipment located at one office while that portion ofthe drawings at the right of the heavy dashed line of Fig., 2 and thoseshown in'F-ig. 3 represent the circuits of a second otlice. At the upperleft hand corner of Fig. 1 there is represented the sub-station circuitsof'a calling subscriber as well as a portion of an A operators cordcircuit. At the lower left hand corner of Fig. Ithere is represented aset of ten numerical keys and it is to be understood that there is oneset of these keys at each operators position. At the middle'and upperportion of the sheet of Fig. 1 there is represented a switch referred toas a link finder of which there is one such switch for each otlice keyat each operators position. At the center and right of Fig. 1 therer isrepresented a trunk finder switch and a sender finder switch, thebrushes of which are connected togetherby a circuit referred to as alink circuit which link is located by the link finder. The trunk finderfunctions toselect any idle one of a group of trunks to the wantedollice, while the sender nder locates a sender ofthe common group of.senders which has been preselected'by a preselector switch shown at thebottom of Fig. 1.

At 'the lower right hand corner of Fig. 1

`and the left-hand corner ofiFig. 2 there is represented a progressivelymovable switch, herein referred to as a sender switch, While 1n thelowerpart of Fig.`1 and in, Fig. 4L

there lare shown the relay registers for storing up the designation ofthe thousands, hundreds, tens, units Aand stations designation.` r11-Atthe upper left-hand cornerl of Fig.` is shown a portion of an inhereindesignated Mannil dicating board common to a plurality of operatorspositions and of'` which therev lis one such board for each"oflicereached Ifrom they` first, mentioned office. Qn this Board there arelocated"` ai., plurality,` of.' lamps for indicating the tens and unitsdesignation ofvany automatically assigned trunk teva-twanted.. office..At the center of Fig. 2 there --appears a progressively movable switch,herein referred to asa receiver switch 'andat the upperportion ofFigs.f2 and 3,

there appears a representation ofthe Beperator7s cord circuit, while atthe lowerpart ofFigs. 2 and 3 thereisrepresented the lineindicatorvlamps and they relays forlcontrolling the same.k f

It will be understood 4thatthenumber.

oftrunkssuchgas that showngat the upper portion4 of Figs. 1 and l2will.,vary in accordance with" the `traiic between the: rvariousoiiices, similarly the number of senders fol-the .usef of all; A`operators positions loy cated .at the 1- same oiiice willdependfon lthenumber of lsiinultaneous callstherefrom,y

It isbelievedfthatjthe invention will best ,v bennderstood by describingthemethod of operation employedin establishing a telephone connectionfrom the sub-station of a calling `subscriber indicated at A to thesubstation of awanted subscriber, ,BQ Whose tel-A ephone lineterminates' in another exchange .Y When the calling subscriber removeshis receiver from its switchfhool,I the line .relay 5 isy operated inythe well* known t mannerr to i light the. line lamp-6*. The Ay operatorthen insertsthci kmay bevconnecztedfto the callingline throughthe-operation-,odwell known automatic connesting means so that` theoperator may inquire/the designation ofthe Wanted subscifiberisilrine.li n y For purposes 'of "this description, it has `been; assumed that theline of the `wanted sub-` scriber terminates at ythe ,Mainl exchange andthat its designation is 7764-R. The" A operator then presses the oiiiceley Aof the "Main7 otiice, herein designated 12, which is effective toclose a circuit from ground at the armatureandbacl; contact of relay 13,lower armature .and back contact of ductor 16, contacts of theoiiice key12, upper winding `ofi relay I17 to"`r grounded battery.y

The relay 17 attracts its arlnaturefas the resuit of theelosnre of thiscircuit and closes f a locking circuit for itself from ground at itsinnerupperarmature and front contact, its lower winding, continuityspringand contactof relay 18, contacts oi" Wipeout key 19,l

winding of relay 14, armature, backcontact randwinding of, the` motormagnet I2Q of the sender'` p reselectorto grounded, battery.

The motor magnet will not operate in series n with thementioned'relays,but the relay 14 is actuated and the relay .17` is heldoperated in ythe last describedcircuit. As soony as ,relay 1.4 operates,itcloses multiple actuatingcir# cuits .for `relay 21,A which connects;the` opera,-

torsfnuinercal key set to the preselected` sender and the key` setlamp'22which indi` cates this connection. These circuits ,extend `fromgroundedbatteryQwindingo relay 21;,-

lower i'ront contact, and, armature yof relay 14, back` contact andarmature of lrelay `13 to ground. The lighting yof the key set lampindicates tothe operator, that thedigits `keys appearing at the lowerleftfhandfcorner of Figure lmay be operated in accordance with relay 14,conn the. designation'of4 the wantedy number.4 The operation ofrelay y11i also` closes a circuit-for actuating relays 23 and25yinseries, thiscircuit extending fromgro-und, winding-of relay 28, upper ,front contactand armature oi"` relay 14, sender preselector brush 24 andwindfing yofrelay 2`5-togrounded battery. Theop- ,y

eration of relay 25 closes atits armature and front contact, a circuityfrom ground over conductor 31, armaturefand baclr contacts yof relay32and the rswitching relays 27, 28, 29

and! 30 of the stations, units, tensandhundreds registers, overconductor 83rightfhand i winding of the thousands register switchingrelay 2,6, conductor 3ft, to grounded battery for actuating relay 26. y

When relay' 17 attracts itsarmatureathe operating and testcircuitsofthe'linl finder,

individual to the group. of. trunks assigned ,to

the Main7 oftice, are: closed, The operating circuit the `li'nl*L finderis closed from grounded battery, resistance, armatureand contact 124 ofrelay 175bag-cli?,` contact, .armature kand Winding' oflinotor magnet42,0011- tinuity spring andy each ,cmf'rtact` of relaygO to ground,r andadvances the brushes yuntil an` idle linl; circuit whereupon thetestcircuit is coinpletedffrom groundat the make-busyrrelay36,.,rightfhand back contact and armature offrelay 37, con# ductorBS,backconrtactand armature ofy relay 39 test brush, `right-hand Winding ofrelay 40, front Contact and armature of relay 17, conductor 41,resistance to grounded battery. This last named circuit is effective toshunt the motor magnet-42 of the link finder which then stops itsbrushes 43, 44, and 45 in engagement with the terminals of an idle linkcircuit.v The relay is operated in the last described circuitV andcloses a locking circuit for itself from ground, winding of relay 39,holding brush of the link iinder, left-- hand highresistance winding ofrelay 40, its inner armature and continuity spring,.winding of themotormagnet 42, its armature and back contact, lower front contact 124and armature of relay 17, conductor 41 and resistance to groundedbattery1 The operation of relay 39 renders the chosen link unselectable.

lAlso when the relay 39 is operated, it closes operating circuitsfor thetrunk finder switch and fort-he sender finder switch, the iirst oitheseswitches being advanced in a circuit completed from ground, uppercontact and continuity spring ot relay 47, winding of inotor magnet 43of thetrunk finder, its armature and back contact, inner front contactand armature of relay 39, outer back contact and armature of relay 37,through the resistance to grounded battery. Under the control of thiscircuit, the trunk iinder switch advances itsbrushes 50,51, 52, 53 and54, until its test brush 54'engages a test terminal having groundpotential applied at the lefthand armature and back contact of relaywhereupon the circuit is closed through the lower winding otn relay 47,front contact and armature of relay 39', back Contact and armature ofrelay 37, resistance to grounded batterv. v

This circuit is eiiie'ctive to stop thetrunk iinder and also to energizethe relay 47 which thereupon closes a locking circuit for itselt fromground at the armature and back contact of a relay similar to 55'atanother trunk over the multiple connection 218, lett-hand winding ofrelay 55, holding brush 53, high resistance winding of relay 47, itsupperV armature. and continuity spring, winding ot' motor magnet 48, itsarmature and back contact, to grounded battery through the contacts andarmatures of relays 39 and 37, as previously described. y

In the event that all the trunks leading from the terminals of a trunktinder are busy, all the relays such as 55 ot' this group of trunks willbe operated, thus removing the short-circuit from the common makebusyrelay 36, permitting this last named relay to operate and disconnect thestopping ground potential from all the test terminals at the link finderswitches, thus preventing anyl link findertrom selecting a link circuithaving no `availableoutgoing trunk at the trunkinder switch.

The operating circuit of the sender finder is traceable from groundedbattery through the resistance, Vouter right-hand armature and frontcontact of relay 39, back contact, armature and winding of the-motormagnet 56 of the sendentinder, continuity spring Y and contact of relay57 to ground. `This last described circuit causes the motor magnet 56 ofthe sender iinder to advance brushes Y58, 59, 60, G1 and 62 of thisswitchv 'until it reaches the same sender to which the key set isconnected by way of the preselector switch.V At this time, ground at thearmature and front contact of relay v23 is extended through brush 64 ofthe Asender preselector, test brush 52' of the sender iinder, upperwinding of relay 57, outer right-hand front Contact and armature ofrelay 39 and resistance to grounded battery. :The relay 57 is thusactuated and at its lower contact and continuity spring opens theenergizing circuitof the motor magnet 56iand linstead closes a circuitfrom grounded battery, outer armature and front contact of relay 37,back contact armature and winding of motor magnet'56, continuity springand armature of relay 57, through the high resistance winding'ot thisrelay, holding brush 61 of the sender tinder,windingof relay 65 toground. The operation of relay 65 closes an actuating circuit for relay25 and simultaneously applies ground potential to the sender preselectorbrush 24thereby short-circuiting the relay 23 to remove the stoppingground potential from this terminal of the sender finders thus makingthis sender busy. It will be seen that the relay 25 will remain operatedasv long as the relay 65 attracts its armature and thus controls thelocking ground :for the relay registers and also controls the release ofthe step-by-step sender. it willbe remembered that earlier in thisdescription it was stated'that-the relay 21 attracted its armatures toconnect the set of numerical keys to the registers. The appa.- ratus isnow in condition to receive the designation of the wanted telephonelline.

Since it has been assumed that the Wanted number is 77 Gli-R, theoperator will thereupon depress the No. 7 numerical key of the key setto close a circuit from ground, spring contacts 75, conductor 76,innermost lower armature and front contact of relay 21, brush 77 of thesender preselector switch, left-hand armature and front contact ofrelayQG, lower winding of the sensitive relay 7 S and lower winding ofthe marginal relay 79, winding of relay 80, to grounded battery. Relays78, 79 and 80 all operate in series and the first two mentioned relaysclose locking circuits through their upper windings, front contacts andarmatures, through. conductor 31, front contact and armature of relay25, to ground. -The operat-ionot relay 8O closes an energizing circuitfor the relay 81 from battery, through its right-hand winding andthrough the armature and continuity spring of relay'80, to4 ground. nRelay 81/tliencloses a lockingv circuit through the'left Winding `ofrelay26 to'grounded kbattery over conductor A34k. lVVhenfthe No. 7.1k`eyis released, relay l 80 retracts its i armature and thereby closes a'-holdingcircuit `for relay 81 which extends from -groundatrthecontinuity spring and contactxlofrelay 89, left-hand winding, frontContact,andarmature of relay 81, armature 82 and front contact ofre1ay26,righthand winding 'of 'the hundreds register switching relay 30to grounded ybattery'for operating this'relay.` The primary lockingcircuitfor n relay 30* extends` from grounded battery,-

left-hand"Winding-*front contact and armature ofrelayfoonductor 83, toground at armatureandcontact of .relay 81. The relay on'operating closesa second locking cir? cuit for itself from'. grounded battery,`

through its right-hand Winding, `front con-` tact and varmature andthrough theback con.- tacts andarmatures of relays 29, 28,27and 32, overconductor 31 to theholding ground at the armature' andv yfront Contactof relay i 25'. This last describedcircuit alsois'eifectiye toshort-circuit the left-hand winding' of relay 81,` softhat this lastnamed relay deen'ergizes and retractsf its armatures;` Thedeenergization ofA relay 81 opens the holding circuit `for thethousandsregister sjwit'cl'i-` ingv relay 26l which' extended `through theleft-handwinding, front Contact anclfarniature,..to groundatzrelay 81.`The switching relay y26 thereupon. deenergizes and disconsf nects thethousands register rela-ys from the controlof the numerical? key set,but relay ySOjlias already extended this key set to" the four relays ofthe hundreds register. Since the hundreds digit of the wantedlnumber is7, the operator lagain depresses keyLNo.;7 to` closeafcircui't" fromground,r keycontact 75, conductor 76,?inner lower' armature and; frontContact of relay 21, sender preselecto'r brush 77, conductor 93',armature 86y and front Contact of relay 30, lowei'windings of sensitive`relay '87yan-d. marginal relay 88, Winding of relay 8O,` to groundedbattery.:

` Relays 84?, 88 and k80are operated and the registerrelays 87 and 88close locking' cirr-y cuits through. their upper windings', frontcontacts andarmatUresOVer conductor 31,1 to ground at the contact andarmature of re lay When key No; 7 is released, relay 80'deenergizes yandagaincompletes a: lock- .Y ing circuit for relay 81' (whichWasenergize'd' simultaneously with relay 80') from' ground y at thecontinuity, spring and contact of relay 1 f 80,.winding rof relay 81,its frontcon'tact `and armature', armature 82and back Contact ofswitching relay 26, armature 88 and front contact -o relay 30,right-hand winding `of thel tens registen switching. relay ,29'v to 1grounded battery.y The vswitching relay 29 ,attractsfitsa.armatures andcloses two` look"-A ing circuits. for:` itself; ythe firstextended fromgrounded battery, through its left hand: Winding, front contact andarmature, conductor 83, outer armature and front con= tact of'relay 81to ground, which circuit insures that the relay29 will be held by itssecond locking circuit including its right`- hand winding, front contactand armature through the back-contacts and armatures of relays 28, 27and 32 over conductor 31,-to"

groundi The tens register is now in condi- 'tion` to be adjusted inaccordance with the tens `digit. of the Wanted number; which in `thecase assumed isf.- rEhe operator there#L uponfdep'resses key' 6 ytoclose vone circuit from f ground, through the resistance, key" contacts90, conductor 76, innermost arma; ture and frontycontact of relay 21,sender preselector brush 77, conductor; 93, armature gaand front contactof relay ,29, lower Windings of the 'sensitive register relay 95 andmarginal relay 96, through the Winding of relayg8'0, to groundedbattery# The sensi;

tive relay' 95 and the relay 80 are energized inthi's series circuit'butthe marginal relay 96 `remains inert.r On the'operationof `relay `95, aylocking circuit` is closed through its upper winding, frontA contact andarmature, over conductor 31 to the holding ground. Then the operatordepresses numerical key No. 6, a second cireuitis closed from ground,resistance, key contacts 90, conductorv 91, lowerniost armature andfront contactvof relay 21, senderpreselector brush 92, con.- ductor 85,voutermost armature' and front contact of the tens switching relay 29,upper kwindings of ,the ysensitiverelay 227r and inarginal. relay 228,yconductor 103, toy grounded battery through the winding of relay 80. Themarginal relay 2281 does-not operate in rthe circuit but the sensitiverelay 227 is ene i ergized and closes a locking'circuit for itselfthrough its lower winding, front contact and armature to' the holdingground. of con# ducter'l. @n thei energization ol' relay 80, anoperating.. circuit is 1 closed through the right-hand winding ,ofrclay81 for operat ingit: jThis closes a vtemporary holding circuit from`ground at the `outer front- .contact and armature of relay 8l,conductor83, ar

mature, front contactand left-hand Winding of relay l29,\to groundedbattery over conductor w42k This circuit insures that the relay 29 willlremain energized, untilits lock`-` ing` circuit through its right-handwinding` is completed. `l/Vhen the" numerical key No.: 6lisre'lea'se'd,y relay 80 de'energizes and loch-` in'g. 'circuit'.` isclosed-through the' left-hand digit of' the wanted number which, in thisinstance, is No. 4. The operator now depresses numerical key No. 4 andthereby closes circuit trom ground. through the contacts 98, conductor99, upper armatureV f' Since the wanted subscriber isl party R, the

operator presses the party key for this party which, in this instance,is the same as the numerical key for No. 3. On the operation 'of thiskey a circuit is closed from ground,

resistance, key contacts 104, conductor 76, innermost armatureand frontcontact of relayY 21, sender preselector brush 77, conductor 93,armature 105 and lfront contact of switching relay 27, lowerwindings ofsensitive relay 165 and marginal relay 226, through conductor 103 andwinding lof relay to grounded battery. The marginal relay 226 does notoperate in series with the mentioned resistance, butthe sensitive .relay165 attracts its armature and locks itself operated through its upperwinding, front lcontact and armature to ground, over conductor 31. f

In the event that the wanted number is an individual line without theparty letter, the o'perationof the start key 108 functions the same asoperating the key for party 'J which key Yoperates relayv 106 ci". thestations register. This will indicate to the yB operator that station JVis wanted and, when she operates the ringing key for party J, 33 cycleringing current .is'selected which will sign al the individual line. Itwill thus be seen that when the start key is operated on a call ttor alparty lineother than party J,

rela-y 106 will not be operatedY because of Y the tact that theoperation and release ofa key to operate a relay of' the stationsregister releasesthe relay 27 so that any subsequent operation of thevnumerical keys will not etlect the adjustment of any Aot the registers.

After the A operator has adiusted the numerical registers in accordancewith the designation of the wanted number, the start key 108 isdepressed and held until the indicator pilot lamp 109 of Fig. '1.islighted lThe lighting kof the lamp 109 'iseifectedr by the closure vottheV circuit including `the conductor V111 which is closed at theleft-hand armature I and :trout contact of relay 110 which relay isoperated will now be described.v 'On the depression of the start key, acircuit is closed from grounded battery, resistance, upper Contact otstart key 108. winding of relay 18, y

conductor 112, outer lett-hand armature and front Contact of relay 40(which it will be remembered was energized as soon as the link under ci1 had seized an idle link), lefthand winding of relay A110, `through theback contactsl and continuitysprings of other relays similar `tov relay110 ot' other positions located at link finders ,operated from `the Mainoiice keys, to ground. AIt will thus be seen that if no .other operatorhas a start key similar to 108 depressed von a.V call to the Main7otlice, relay-,110 will operate'and lock itself operated through itscontinuity spring, armature and right-hand winding and uppermostarmature and frontcontact of relay 17. Relay 110 on attracting itsarmatures breaks the series ground circuit which is arranged so that noother operator .can

"disturb the connection under completionuntil the operator in attendanceon the present call has released her start-key and then only oneAoperator can ei'ectthe operationv of the relay corresponding to 110 atanother positionj. When 110 attractsits armatures in the mannerdescribed, it'closes a circuittolight theindicator pilot lamp-,as:previously ldescribed which inforins the operator that the cord circuitin her positionis associated with the common indicator board shown inthel vcloses an actuatingrircuit for relays 37,

116 and 117 extending iromgrounded battery, right-hand winding ofrelayv37, inner- Y most front contact and armature of relay 113,

uppermost` fronti contact 'and armature of relay 47, armature andbackcontact of relay 115, trunk finder brush 52, winding of sensi'- tiverelayllG, winding of marginal relay 117,

front contact -and armature of relay 55 which was'en'ergized in serieswith relay 47) to ground.` The operation"A of relay 117 is eective tolight the-tens and units lamps on the indicator board to indicate thetrunk designation of the'trunk assigned .for use, into the jack of'which 118 the operator-Will insert'the callingplug 119 other cordcircuit. In the drawing, this trunk is shownas rtrunk No; 12 andthemarginal relay 117 completes circuits to light the tens lamp 120=and thell) i units lamp 121. On receiving this number indication,y the operatorinserts the calling plug-119ofthe cord circuit taken' for use into fthejack 118 and releases the start key108` y which extinguishes thelamps on the common indicator board as will be pointed out. When thestart key 108 is released, at its upper con.-`

tacts .y it yopens the circuit which has been `locking the relay 17operatedand since'the relay `18 is slow to releaseits armature, theoriginal locking circuitof relay 17 is open at the continuity spring andcontact of relay 18. 'Therefore-r the relay' 17 deenergizes and as soonasit retracts its armatures, it opens the locking circuit yfor relay 110which extended throughthe uppermost front contact and ar- .in .usearefnovv in normal condition and in readiness for use on asubsequent'call. h y #When relay 113 of the trunk finder is re.- leased,as .above described, the lovvresistance Winding of relayA A37 is,disconnected from the* windings ofthe sensitive relay` 1.16 andymarginalrelay -117 of the trunk circuit. -Relay 37 and "relayl 1.16,however, do not deenerf Ainthis .circuit,` lthe marginal relay 11.7 de.-

gizeybecause of `a circuit extending from" grounded' battery .throughbotlil windings iii "series 'ofrelay-B', its inner front contact and.'

armature, varnriati'ire andbackcontact of relay-115, finderbrush `52,yrelays 116 fand 1,17, to ground at .i the front contact and armatureofrelay 55. Because of the high Eresistance Windlgof relay 37.1'1cwincluded energizesf'andextinguislies the lamps onfthe A,indicatorboardWhich have `been lighted for indicatingthe'trunkl assignment, 'Relay 37fnow holds thetrunk 4finder busyand also causes the sensitiverelay`1`16`ofthe trunkr` `andthe"relay 570i the leender, finder `toremain'operated. Sincev they calling plug 119 ofthe operators cordkcircuit, `isin` engagement `with' the jackl contactsy 11S-,ofiftruifilrwllo.D 12,'the relay ishovvnattheriglit of Fig; 1r

"is held `operated ronr grounded battery,

i @through thesleevecontacts of the .mentioned .Y plug; and ack `andlWinding' of 'the relay.` 55 to `ground 'over conductor' 21,8,atdthefarmatu-re an'djbackcontact'of a relay similar to at.

another trunk"of'thi's'r group; Relay wliile operated," indicatesy thattrunk No. 12- is in "usexff f bof fan. operators position such as. thatlshown 'at the/lower lefthandfc'orner of. Fig. .1 isre- `leased,it`i'sjimtnediately connected toy an. idle registerfsender ofthe common`,groupwof L fregister `senders offwhich there are only enough'vprovided 'to handle. `simultaneously calls to allA oiices, duringftheinterval that .transpires between the depression of the of-L tice-keryibyfthe Aoperator, until the number indicationlias been transferredlto the op? erators number indicator It Will be recalled that When relay18Was energized at the close of the 4operation of the numerical keys,relay 14 deenergized. This closed an energizing c-ircuit for relay 13 aslong as preselector brush 24 tested test contacts having a busypotential applied at the armature and `front contacts ofrelays similarto f relay 65 at 'engaged register senders. With.

relay 13 operated, motor. .magnet 2OI advances the `preselector tersender.

I As soon as the'number has been set upon the'key sety in the mannerindicated and when the start key is ..0peratefl,v thel operator`receivesfthe. trunk assignment by the `lightling oftrunl` indicatorlamps, such as 120 and 121 on the commonindieator board and thus it isnot necessary -orf'thisy trunk assignment` -to "be transmltteclto `the Aoperator from 'the'B opierators positionover anorder Wire.

w `It..jvvill be understood that the; registers of a-.iregisterl sender.remain adjusted to store upwthe numberfdesignation of the` Wantedniimber untili the B operator is inv readiness to receive this'yindication 'on'.thef number 1n.`

dicator shown. at ythe right of Fig. 2 and at thelower partof Fig. 3,.thus it is" not necesf. sary for. the Aoperator 'to repeat the wanted.

number tothe Boperator. It will vbe pointed out in this description `howythe Wanted num.- ber 1s displayed 'on'. the indicator at the rB brushto select an idleregissof position. untilltheB operator is in readinessvto `attend to thefcall` and it remains as af visu-al indication of the`Wantednumlocr un.- til the, By operator extinguishers the ope-r.-

Aatednumber indicatingflamps either by operating a common release. key125. orby insert-ing the plug 126 into a. multipleiack127 of' thewantedv line.

The Boperator receives an indication that Va' connection 1s Wanted overselected'trunk No. 12 when the A. operator ".depresses the sta-rt key108 of Fig. 1, which operation closes acircu'it` from ground, .Windingof relayf129 of Fig..2,sender1brush 130 `infits normalposition,..conductor 131, sender iiiider brush 60, lovvermost frontcontact andarmatureof` relay 57, conductor 132, trunk finder brush50,"..upp'ermost lfront contact and armature l Aof relay 116, tipicondructorl of the `assigned trunk," .uppermost armature and" backContact of relay 184;', Winding of the repeating coilv and windingofrelay 135, to groundedbatteryhr Relays129 and 135 are both operated,vrelay 129 closing acircuit to advance the sender switch into its Zero.positit'nrl This circuit istraceable from ground, armature i and frontcontact ofilfrelayl 129,.. sender br b 1:36 ,conductor 1.37 backcontact,armature and winding of motor magnet 126 of the sender switch,to grounded battery. .The operation of relay 135 closes a circuit foroperating the slow releasing relay 138' and this relay connects the lamp139 in circuit with the intermittently closed contacts 140 of the commonflashing device, this circuit being traced from grounded' battery,through the lamp 139, inner' armature and front contact ot relay 138,armature and back contact of relay 141, 'conductor 142, contacts of theflasher 140, to ground. On noting that lainp 139 is intermittentlylighted. the operator presses the assignment key 143 and thereby Vclosesa circuitfor operating the relay 134 which extends from ground, throughthe contacts of this key, upper winding of relay 134, conductor 144,receiver brush 145 in its normal position, armature, back Contact andwinding of the motor magnet 146, to grounded battery.v This circuit iseffective to cause the energization of the relay 134 which the-ref uponcloses a locking circuit for itself irom grounded battery, contacts onthe release key 125, conductor 147 winding of relay 148, conductor 149,lower winding, front- Contact and armature ofrelay 134, conductor 150,to

' ground at the inner armature and back contact of relay 151. Theguard'la'mp 152 is energized in multiple -with this last describedcircuit. Relay 148 is operated yin the locking circuit -just describedand 'closes an operating circuit for the motor magnet 146 ofthe receiverswitch to advance it into position '1, This circuit is traceable from.

lgrounded battery,v winding oit/motor magnet 146, its back'contactandfarmature, receiver brush 145 in its normal position, right-handvfront lcontact and armature of relay to ground. As soon as the receiverswitch moves 'out of itsnormal position. no other relay such as 134 canbe operated by falsely press-v ing another assignn'ient key,because thebattery 'potential throughf the ywinding 'of the motor magnet 146 isremovedfrom these relays when the receiverswitch leaves its normalposition. The operation of relay 134 also disconnects the tip and ringconductors -133 and 153 frolnthe Bf'operators cord circuit and connectsthese conductors to the brushes 154 and 155 of the receiver switch. Theopening of conductor 133 causes relay to'deenergize and also e'lectsthedeenergization of relay 129, which in turn advances the sender switchinto position 1;

It willnow be explained'how the receiverL and'sender switches areadvanced step-bystep in synchronism and how the number d esignationrecordedv on the relay registers at the Aoperators position is effectiveto actuate corresponding relays at theV B operators position of thewanted otlice. The stationsdesignation is transferred to the lrelays ofthe B operators position iirst so that this operator 'can depressthestations key Whilethe remainder of the wanted number designation isbeing received. Since the receiver and sender switches step alternatelyand since each switch must complete twentyone steps to effect-the numberdesignation at the registers of the B operators position, the totalnumber of steps taken by both of these switches is forty-two and willrequire about one second of timeto display the complete designation ofthe wanted line, after the B operator presses the Vassignment key 143.

It willbe remembered that the sender and receiver switches are each inVposition 1 so that a circuit is now extended from ground,

Winding of relay 160.` conductor 161, brush 154, uppermost front contactand armature of relay 134, tip conductor 133 of the selected trunk,uppermost armature and front contact of relay 116, trunk inder'brush 50,conductor 132, lowermost armature and Jfront contact of relay 57, senderfinder brush 60, conductor 131,'brush 130 in position 1, conductor 162,upper front contact of relay 106, but,

`since relay 106 was notY operated, this rcircuit is incomplete at thispoint. At this time a circuit is closed from ground through the lowresistance winding of relay 166, brush 155,`inner upper armature andfront-contact of relay 134. ring conductor 153, of the trunk selected,inner upper armature and front conv tact of relay 116, trunk finderbrush 51, con-- ducto-r 167, armature andfront vcontact of relay 57,sender linder brush 59, brush 163 in position 1, throughboth windings inse-` ries of relay 169, to grounded battery. Y he relay 166 will notoperate in series with the high and low resistance windings of relay'selected trunk through brush and low resistance winding 'of the relay166,H to ground.V Relay 166, is energized in this circuit and causes themotor magnet 146 of the. receiver switch'to be advanced in .a circuittraceable from'grounded battery, winding, back contact and Aarmature ofthis magnet, brush 171 in position 1, front Contact and armature ofrelay 166, to ground. In position 2 of the receiver switch, the relay192 is connected tothe stations register of the A office over a circuitextending from grounded battery, conductor 231, winding otl A relay 192,conductor 232, receiver brush Y154 iny its second position, uppermostfront centact and armature of relay 134, tip conductor through bothhighand` lowresistance wind' y ings of'relay 166, to ground'. `The relay166 deenergize-s yand thereby completes; a circuit `forthe motor magnetA"1461 to "advance theyre-*i Cei-ver switch into position.- Asvsoonasthey 13.3, 'ofthe ,selected trunk, upper larrnatu,re and -front`contact of relay 116,tr.ui1l{ inder bnushO, conductor 132, 4lowerrnostarlnat and trent .contact of `relay '57, sender in'der brush 60,conductor 131;, sender switch brnsh 130,k `in itssecond position,conductor ,234,

but this ,circuit is incomplete at :the upper front contant and armatureot'relay 107 that relayy 192 is not operated.`` "While thereceiverswitch 'is in position 2, the'high ref sistance winding of relay166 is connected in .series with the low resistance winding of relay 169atthe sender switch,causingithis.

last'mentioned relay to deenergifze `while the relay 1.66 at therecei-ver 'switch'.reinainsoperated.,y The sender switch is now advancedto position 3 in al circuit traceable-troni grounded battery, Windingvof its motor inag= net 126, armature and yibacln contact 4of thisYmagnet conductor. 137, brush 186, conductor `170, hack contactandarmature of relay 169 to ground. y Inv position of the sender switch i acircuit is elosedyfroxn ground through both windingsof relay 17,3, brush168 of the sender switch, brush` 5910i. 'the' sender linderswitch,`middley contact and `armature ofy relay ,57, conductor 167,.trunkiinder brush; :51, inner `:Front `contact andarmature of relay overring .Conductor i153 of the trunk, inner arma*- ture andfront Contact ofrelay 13d, receiverV switch brush 155 yin `its second position,

:r receiver switch enters `this position', acircnit 'uppermostarmature.and front: contactinfis closed fork operating relay193,2.extending from ground, winding ofl this relayycondiietor23f5,receiver switch brush 154, upper-V mostffront contact ,andA armature ofrelay 1,34, tip conductor 133 of the selected trunk,

k vrelay 116, trunk'finder 4brush 50, conductor 132,y lowerinostarmature `and front` contact of relay 57, sender `finder brush`60,1eondu`ctor131sender switch'brnsh 130, kconductor `236,lowerinostgfront contact and/armature -of relay f165, resistance togroundedjbattery,

The relay 1,93, when.operated`closes a locking/circuit 'for itselffronijground,Y through its winding, front contactand.` armature overjconductorQ-B to lockingl battery.- rlfliefst'a-` i f the lowresstancewinding* oirelay: 172,

' 173 is operated in this circuit and at ritsfifront f "thislastdescribed circuit of relay 19.3..` 1 circuit isfalsoclosed -roinbattery, throiigi tions vlamp c 16d is` lighted in inultinle :with fili;i

brush 155, over the circuit,previously de scribed toyb'rush y16,8 ofthesender switchin position, through the-high anld; low resistancewindingsof relay 173,L to ground. `'Relay contact vand armature closes an`operating cir .cuitv for-fthe, Inotorzymagnet '126 .which advannes thesender switch into )position L1. :,-n

- erate a relay at the Wanted office..l

y mese this position, the low resistancewinding Lof to energize relay172, which closes an .operating clrcuit for magnet 1,46 of therrec-eiverswitch for' advancing this `switch into position 4. j Thehigh resistancewinding ,of relaV 172 `1s now included 1n the/circuit extending overtrunk conductor 153 and through the,y low resistance winding; of relay173 which causes :this lastnamed relay to `deenergize 172, to batterypotential. This causes rel-ay 172vto` deenergize and advance thereceiver switchI into position.y This alternate oper ,ation of thesender `and receiver switches con.- e

tinues, untilboth switches `are,advanced position 21. 1 e y It ywillseeny that thebrush 154 `of the receiver connects the twenty Lrelays,.Ato l where battery potential is extended yrelay, 173 is connected totrunk conductor' 1:53

inclusive, of the indicator successively tothe f tip conductor 13S-.ofthe selected trunk as the .receiver switch advances its brushes throughpositions '1 to .20, inclusive. Thebrush I130 of the `sender switchAconnects thefmentioned tip conductor 133`of the selected trunksuc-`cessiv'elyto corresponding relays of theregf isters and'theregisterrelays which have been i r:

\ operatedin response toL the rdepression ofthe numerical keyswillcloseqcircuits to operate and lock corresponding relaysat:theindica-` e tor atthewanted oliice. lIt should be notedy thattherelays of the registersender and of theindi'cating devicefare soconnected to the various contacts ofthe sender switch and receiverswitch,.fthat"as these switches are ad` vanced, current 1s reversed:y1n` the signaling circuit, init eachsuc'ceeding position oifthese.

switches. Inthis waythe-overlap, when the sender switch In the caseassumed, relaysA, B, E, :1,

locked foperatedin response tothe depress sion ofthe proper, keysr ofthe numerical key kset and, after theoperationof the. sender andreceiver switches has taken place,corre spending relays will be`energized and locked operated in the receiver ofthe distant oice.

With these last mentioned relays operated,

vcircuits can readilybe ytraced for lighting n only the .statons lamp R,thousands `lamp No. 7, hundreds lamp No.7,tens1la1np No. Gand units lampNo. 4. 7 C 1 When the vsender switch. reachesposition ,f 21, a circuitis closed from grounded battery,

winding of magneti126,conductor 137, brush 13.6, conductor 180,? senderiinderbrnshfiS, i 5

moves, will not falsely ops.V

'tief `K, N andof/the. sender'registers were upper armature and frontcontact of relay 57, winding of relay 115, to ground. The Y magnet k126remains inert, but the relay 115 is operated to open the operatingcircuit of the relay 116 of the trunk and the operating circuit of relay37 of the trunk finder. Relay 37 in turn opens the holding circuit ofrelay 57 of the sender finder switch and the relay 65 of the senderwhich relay in turn causes relay to deenergizeA l/Vhen relay 25 retractsits armature, it closes a circuit from ground, through the sender switchbrush 128, conductor 127, back contact, armature and winding of motormagnet 126 to grounded battery andthereby advances the sender switchinto its normal position, while the relay 25 at its frontcontact opensthe locking circuit which has been holding the actuated relays of theregisters-in operated position. The trunk finder and the sender finderremain in the position last used.

After the' lighting of the indicator lamps rat the distant office, the Boperator notes the designation of the wanted line and tests the multipleof the wanted line in the well known manner and, if this line is idle,inserts the plug 126v intogthe multiple jack 127 of this line. This lastoperation actuatesthe sleeve relay' 151 which thereupon opens ltheconductor 150 by which the relay 134 and relay V148 have been heldoperated. Relay 134 deenergizes and extends the conductors 133 and 153of the selectedtrunk through the windings of the repeating coil ofthe Boperators cord circ-uit'. The relay 148 upon. deenergizing closes a`circuit *from ground, through its armature and back contact,

L brush 145 of the receiver switch, armature,

back contact and winding of the motor magnet 146 to grounded batterywhich circuit is effective to advance the receiver switch to its relay141, uppermost front contact and armature of relay 138.,to ground. Relay242 is actuated in this circuit andlocks itself operated from a circuitrclosed 'from` grounded battery, its lower winding, front contact andarmature, to ground at the uppermost front contactand armature of relay138. The relay 141 is operated in multiple with the last describedcircuit through its continuity spring Aand Contact and, when operated,closes a locking circuit for itself through its continuity spring andarmature. As soon as the relay 242,. is operated, tCIQSESaIIIgngcircuit-from the source of current through the depressed partyke-y 190and in ser-ies through the back contacts ofkeys 189 and 188, conduct-or243, lower front' contact andarmature of relay '138,-winding of tripvrelay 244, upper front contact and armature of ringing relay242.tl1rough the lower side of the opera-tors cord circuit and calledline in series, through the tuned ringer at the B subscribers stationover the upper side. of this line and the operatcrs cord circuit inseries to ground at the uppermost armature and Ifront contacts ofringing relay 242. When the called party responds, the trip relay 244attracts its armature to shortcircu it the ringing lrelay 242 whichthereupon opens its locking circuit and remainsv inert to preventinadvertent reapplication of signalling'current on this connection.Also, .when the ringing relay 242 retracts its armatures, fit completesa circuit for the.`

circuits by which supervision is obtained since these operations takeplace in the same manner asv in multi-oflice telephone systems now inuse. It will be sufficient to understand that atthe termination of theconversation, proper signals will be displayed to the A and B operatorswho thereupon manually restore the cord circuits which have been in use.

It shouldbe pointed out that the B operatorcan increase the speed ofcompleting connections at her position by operating the com-Ay monrelease key 125, as soon as she has noted thedesignation of the wantedline instead of Waiting for the release operation of the receiver relayregisters to be effectedby inserting the plug 126 into the multiplejack127.

By arranging the incoming trunk circuit with a so-called automatic busytest arrangement, that is, an arrangement wherein the operator doesnot-,have to test the multiple of a wanted line but simply inserts the`plug of 'her cord circuit into a multiple jack of this line whereuponautomatic means completes the connection, if the wanted line is idle,and prevents the completion of this connection, if the wanted liuc isengaged, the B operator need not be pro-vided with a telephone set.lVliile vin this disclosure .manual party keys have been disclosed forselecting the current of proper frequency for selecting wanted stationson a partyjline, it will be understood that the system herein disclosedwill be equally effective, if the signalling current is selectedautomatically.

What-fis claimed is: c i111 a :telephone system, an operators t"position, telephone lines terminating iii-'said position,l a secondoperatorsfposition, other vnect'ing'said positions, a trunk indicatingde- 5 vice atsaid iii'st position, a line indicating device at saidsecond position, means at said yiii-st *position whereby an operatorreceives 2:10' liiection to awant'ed telephone line, means f: `imYen-aia `responsive thereto for selecting an idle trunk to said second`operators position and for causing saidtrunk indicating device to giveltlietrunk indication of the selected trunk line 5f at said iirst`operators position, a-'circuit for connectingv the calling'line andthe'selected trunk, means contr0lled7at1said` first positionfor*causingsaid*line indicating device to givethe designation YoftheIwanted line, and 25""a1manual switch fbyf'nieans of which an operFatorat 'said second positionl connects the *selectedtrunk `totheWantedtelephone line.

` v2. In a] telephone system',vv plurality of operators positions?,-each provided with -a 25numericaly key set,`a plurality of* senderscomnionvto 'said' positions, ineansfor alloty'ting senders or'use',means controlled atan op'erators position for as'so'ciatingitsnujmeiicalkey setwith an allotted sender'wliererolbyVsaid senderis'variably adjusted-in accordaiicewith apredetermined code, lotheropeiatoi"s'`po'sitions' veachr E'provided ywith an "indicating device,an'dmeans underthe con# trolof'asender yfor operatin lin indicating i,"35 devicein accordance-withtlie'adjustinent lof 3. lnatelephonesystem, apluralityot ofices, a plurality oftrunkcircuits connecting oneolice with ai second oice, a'plurality of selecting a'fsender fory useahead ofthe call, a plurality `i'"s'witclies, a'lin'k"circuit'termi-n'ating 'at oneI endl 'inaswitclii'o'r selecting a ti` `kf'circ'uitfvvand terminating at its "other v4;; en in a switch for seizing apieslected sender,

celvlwitlif" a predetermined code,

"forisei ing' a preselected sender,

forfseiziiigaii idle link circuit yind' tl'ier'eb'y efect the operationofH sai' yst y"i1-iid second switches,r an indicatiii'gldv" 'e itythe'ksecond 6.5 coince;`

v i ut terminating atl one endl intafswitcl" fpeiatin'gfto lseize ifaltrunk circuit, said ylink 'rininating 'at itsother end'in' a switchaftliii'd switch nd ineaii'sf cotrolldlby said adj usted "sendeiandconti'olled through said first and A n second switches over aselectedtrunkfor se-v `lines terminating'tli'ereat, trunkcircuitscoiilectively operating said indicating device.

5; The method of completing a. telephone connection which consists inthe subscribei` repeating the number of the wanted line to an operator,aid operator tliereuponmaniially the designation ofwanted lines, meansconftrolled at said position for' initiating a con-A selectingtlie`oiice'through` which a wanted subscribercan be reached, selecting atrunk to ysaid office, visually signalling the desig- '--nation oftlieselected trunk to said operator,

'said operator then connecting the callings'ubsciiber i andthe selectedtrunk, :visually signallingtlie number of the Wanted subscriber r'to asecondv operator, "and connecting the wanted-lineto the designatedtrunk. y

1 6. Ina teleplionesysteni, pluralityof offices, an A operatorsposition-y at onev of said oificesgB Aoperators positions at the otheroffices,ntrunks for `connectingsaidv A operators.

position `to each of 'said' other oiiices,`oiiice keys one foreachoiiice accessible to said A `operators` posit-ion, and means responsiveto the operationof an oiiice key for automatically selecting al'trunk toawaiited oiiice and for automatically `indicating the designation oisaid'trunk to saidA operatorsposition.

7 Ingatelephone system-L a plurality of teleplioiieotlices, anAoperators position at i one of said oiiices, B operators positions at'W the other offices, trunks for connecting said rof one ofsaid keys forautomatically fselectingtrunks toa wanted" office, and automaticindicating means forgiving the designation v' of selected trunks. i i

l8. yIn a telephone system, ja# plurality'` v:telephone oilices",rplura'lityoit A operators positions `at one ofsaid oiii'ces, 'Boperators positions ateachfof saidy other oiiices, trunks leading-fromsaid A operators positions kto eacliiof said'other ft'lces',` an oiiicekeyat each Avoperatons position foreach office reached from-saidfAfocraters ositions a trunk 'indicator at said A;operatorspositions, a-nuinber indicator at each of said distant off "li'ces,` a'pluralityofsender's common to said -opeiiators r`positions" and var-iably`-adjusted therefrom, and `means iesponsiveto the adjustment otsaidsenders for selectivelj operating said number indicators. A i In atelephone j syste- ,fo'iiice's, 'an A'operatorspositioii at `one of saidoffices, a `B `otiticetaKfretgisterseiider at the A oaeratorls"operators position the other` posi o comprising a, group of registersai-y "iran'ged tobeselectively operate'dgunder the fcntrol'ottliecid opy y'movable switch associatedwith l"said register sender, an"indi'eatingl device -at the B operaeifttor, a progressively w'tors'positioma progressively movablesvvitch associated" therewith, andmeans'ior'operatwo telephone ing said switches alternately whereby theregistration on said register' sender is transferred to the indicatingdevice at the B operators position.

10. In a telephone system, an A operators position, register senderincluding a progressively movable switch located at said position, meansat said position for vvariably adjusting said register sender inaccordance with a predetermined code, a B operators position, a trunkcircuit connecting said oper- -ators positions, an indicator at said Boperators position arranged to be variably operated in accordance withthe setting ot said register sender, a. progressively movable switchassociated with said indicator, means for setting said switches inoperation, means effective thereafter whereby the switch associated withsaid indicator completes operating circuits for the switch asociatedwith said register sender and means whereby the switch associated withthe register sender closes operating circuits for the switch associatedwith said indicator, and means functioning during the advance of saidswitches for effecting the operation ot the indicator in accordance withthe adjustment of said register sender. l

l1. In a telephone system, a plurality of othces, a plurality ot Aoperators positions at v one of said offices, a B operators position atthe other oliice, a plurality of register senders for the use said Aoperators `positions arranged to be variably adjusted therefrom, meanstor associating an idle register sender `with an A operators position,each of said register senders being provided. with a progressivelymovable sender switch, a trunk circuit connecting said A operatorspositions and said B operators position, an indicating device located atsaid B operators position and a progressively movable receiver switchyassociated therewith, means for initiating the operation ot` saidswitches, other means eiective thereafter whereby the receiver switchveffects the advance ot the sender switch, additional means whereby thesender switch effects the advancel et said receiverswitch, and meansoperating ander the control et' said switches whereby the registersender eitiects the operation 01"' said 'adicator over said tri'ini:circuit. Y A

1Q. In a telephone system, a plurality ot oiices, plurality ot Aoperatorspositions at one ot said oiiices, a B operators position at theother office, a single strip of keys at cach A operators position, aplurality of register senders for the use oi said A operators positionsand arranged to be variably adjusted by said keys, means for associatingan idle register sender with an A operators position, each of saidregister senders being lprovided with a progressively movable switch, atrunk circuit connecting said A .operatorsfpositionsand said B"operators position, an indicating device located at said B operator-sposition, 'a progressively movable receiver switch associated therewith,means for initiating the operation of said switches, other meanseffective thereafter whereby the receiver switch effects the acvancc ofthc sender switch, additional mea-ns whereby the sender switch etfe'ctsthe advance ot said receiver switch, and means operating under thecontrol of said switcics whereby Y the register' sender eiiects theoperation of said indicator over said trunk circuit.

i3, In a telephone system, a plurality of offices, a plurality ot Aoperators positions at one of said oiiices, a B operators positionkceiver switch effects the advance of the sender switch, additional meanswhereby'the sender switch eiiects the advance oi said receiver switch,and means operating ander the control of said switches whereby theregister sender etieets the operation or" said indicator over saidtrunlr circuit. 1 l

v 14. In a telephone system, a plurality ot offices, a pluralit i of Aoperators positions at one of said o ces, a B operators position at theother oliice, a plurality of register senders for the use of said Aoperators positions, each of said register senders including a pluralityof relays arranged to -be variably adjusted from said operatorspositions, means for associating an idle register sender with an i' Aoperators position, each of said register senders being provided with aprogressively movable sender switch, a `trunlr circuit connecting said Aoperators positions and said B operators position, an indicatingdevicelocated at said B operators position and a progressively movablereceiver switch, yassociated therewith, means for initiating theoperation of said switches,

other means effective Vthereafter whereby the receivery switch effectsthe advance of the sender switch, vadditional means whereby the senderswitch effects the advance of said receiver switchfand means operatingunder thecontrolA of. said switches whereby the register sender effectsthe'oper- Alation of said indicator over said trunk circuit.

15. In a telephone system, a plurality of operators positions,{ each ofsaid positions beingprovided with singleset of keys, a f

16. In a telephone system, an A operators,

position, a B operator-s position, telephone lines terminating at eachof said positions, a trunk circuit extending between said positions, aregister sender in said A operators position arranged to be variablyactuated in accordance With the designa-tionjof a Wanted telephone line,anr indicating device at Vsaid B operators position, and means having asignaling circuit including at least one ot the conductors of saidtrunkcirciiit for transferringthe designationvrecorded on saidregistersenderto said indicating device, said means "including mechanism ltorreversing thev direction of current flow in said signaling circuit aplurality of times `during the trans- ;fer ofthe designation :from saidregister lsender to said indicating device.` f

k17 yIn a teleplionesystem, an A operators position. a B operatorsposition, telephone i lines terminatingv ink said positions, a trunkregister sender at said A operators position arranged to be actuated inaccordance With circuitextending between said positions, a

tliedesignation of a Wanted telephone line, an indicating device atsaidB operators position,a signaling circuit including at least oneconductor of said trunk circuit for trans-` ferring the designation ofsaid register'seiidf er'to. said indicating device, jiiieans at' saidyoperat'ors position for connecting said trunk circuit tothe indicatedline, andtwomeaiis for'releasingsaid registersender andA said receivingdevice prior to theuterminatieii of `the connection. f f

n .18. In a telephone system, ann operators position, a-B operatorsposition, telephone lines terminating at each ofsaid positions, aregistering device located at saidgjin` operators position and arrangedto be actuated in. accordance with the designation ofV a.

Wanted telephone.` line, an, indicating device located at said Boperators p position, asignaling circuit including i at least'.oneconductor 'of said trunk circuit for, transferring 4the designationlofisaidxwanted `telephonev line kvfrom-"said" registering device tosaidlindicat-` ing device, a'release key, andswitching means A'forconnectingv sai-dv trunk :circuit to said Wanted telephone line,` said,release fkey -and eating devices.4 ,n

said switching means beingindividiially effective to release saidregistering yandj indiv19,. Inia't'eleplioiie exchangesysteiinaplurality of operators positions, apluralityct l outgofiiidf'triiiiks, each;A trunk fterinin ating at its. 'distant end mi a`manual :connection-terroperation of said sender controlling ment. i

20'. yIn a telephone exchange system, a plurality ot operatorspositions, a plurality of outgoing trunks, each trunk terminating at itsdistant end in a manual connection terminal, mechanism associable withthe distant ends of said trunks for indicating the numbers of Wantedlines, a plurality of senders, a plurality of sender controllingequipments, a plurality of switching units common to saidoperators"positions, meanss'to operate f a switching unit to establishan interconnection between a sender controlling equipment, a sender andan idle trunk, means to indicate toan opera-tor the number of the idletrunk selected, and means to operate said mechanism over said trunkunder the control of a sender in accordance with the operation o saidsender controlling equipment. f

21. In a telephone exchange system,` in combination, incoming lines,outgoing trunks, each.y trunk terminating at its distant end in amanually-'operable connection terminal, an operators position, a cordcircuit terminating at each enclin amanually operable device forinterconnecting an incoifningv line and an outgoing trunk, mechanismassociable `with the distant ends of said .trunks for indicating thenumbers of Wanted lines, a plurality of vari- `ably r.operable sendersfor controlling said mechanism over said trunks independent of i saidcord circuit, and means at said operator-s `position to control theautomatic selectionot a trunk and tovariably control the settin of saidsenders for controlling said mechanism.

at each end in a manuallyv operable device torintelfCIlIiecting'anincominglline and an outgoingrtiuiik under thecontrol of said'operators position, mechanism associable Witli'thedistantends ofsaidtrunks for indicating the `numbers, of Wanted lines, ayplurality of Vaiiy ably operable senders for transmittingseriesofvimpulses of varying characteristics'overl said' trunks forcontrolling said mechanism, i and" mean-s at said operators position vtocontrol the automatic selectionv of a trunkand ,of a sender and tovariably control thesettiiig y, 22. In a telephone exchange system, inconiy equipment, a sender of said senders for controlling said mechawnism.

23. In a telephone exchange system, in combination, incoming lines,outgoing trunks, each trunk terminating at its distant end in a manuallyoperable connection terminal, an operators position, a cord circuitterminading at each end in a manually operable device forinterconnecting an incoming line and an outgoing trunk under the controlof said operators position, means associable with the distant ends ofsaid trunks for indicating the numbers of wanted lines, a plurality ofsenders for transmitting series of im aulses oi Varying characteristicsover said trunks for controlling said mechanism, registers in saidsenders for recording the digits of wanted line numbers, and means atsaid operators position to control the automatic selection ot a A trunkand of a sender and for Variably controlling the setting of saidregisters for controlling said mechanism.

24. ln a telephone exchange system, a plurality of operators positions,a plurality ont outgoing trunks, each trunk terminating at its distantend in a manually operable connection terminal, mechanism associablewith the distant ends of said trunks tor indicating the numbers ofwanted lines, a plurality of senders, a plurality of sender controllingequipments, a plurality or switching units common to said operatorspositions, means to operate a switching unit to establish aninterconnection between a sender controlling and an idle trunk, means tooperate said mechanism over said trunk under the control of a sender inaccordance with the operation o't said sender controlling mechanism, andmeans operative following the completion of the operation of said senderto release said switching unit.

25. In a telephone exchange system, a plurality of operators positions,other operators positions, a plurality of outgoing trunks, said trunksterminating at said latter positions in manually operable connectionterminals, mechanism associable with the distant ends of said trunks forindicating the numbers o wanted lines, a plurality of senders, aplurality of sender controlling equipments, a plurality of switchingunits common to said lirst operators positions, means to operate aswitching unit to establish an interconnection between a sendercontrolling equipment, a sender and an idle trunk, means to operate saidmechanism over said trunk under the control of a sender in accordancewith the operation of said sender, controlling mechanism and meansoperative upon the response of a second mentioned operator to start saidsender into operation.

26. Ina telephone exchange system, a plurality of incoming lines, aplurality of outgoing trunks, each trunk terminating at its distant endin a manually operable connection terminal, means for interconnectingsaid lines and trunks, mechanism associable with the distant ends ofsaid trunks for indicating the numerical designation of a desired line,a register sender, groups of relay registers for said sender, means forregistering the numerical designation of a desired line on saidregisters, means associated with said sender for transmitting over saidtrunks a plurality ot series of impulses ot varying characteristicscorresponding to the numerical designations registered upon saidregisters tor controlling said mechanism, and means for changing theorder oi transmission of said series o'li impulses.

27. In a telephone exchange system, a plurality of incoming lines, aplurality of outgoing trunks, each trunk terminating at its distant endin a manually operable connection terminal, means. for interconnectingsaid lines and trunks, mechanism associable with the distant ends ofsaid trunks for indicating the numerical designation of a desired line,a register sender, groups of relay registers for said sender, means forregistering the numerical anc stations designations of a desired line onsaid registers, means associated with said sender for transmitting oversaid trunks, a plurality of series of impulses of -varyingcharacteristics corresponding to the designations registered on saidregisters for controlling said mechanism, and means for changing theorder oi transmission of said series oi impulses in accordance with theoperated condition of the relays of certain of said registers.

In witness whereof, I hereunto subscribe my name this 9th day of April,A. D. 1926.

VVINFREI) T. POELL.v

